Swivel joint for construction machinery

Abstract

A swivel joint for a construction machine is disclosed, which is used to connect hydraulic pipes which supply a flow rate from a hydraulic pump mounted on an upper swing structure that swivels against a lower driving structure to components, such as a traveling motor and a steering cylinder, mounted on the lower driving structure. The swivel joint includes a hub mounted on any one of the lower driving structure and the upper swing structure and provided with a hydraulic fluid movement port formed thereon, a shaft mounted on the other of the lower driving structure and the upper swing structure and rotatably coupled to the hub, the shaft having a hydraulic fluid movement path formed in an axis direction to communicate with the port of the hub, and a planar thrust bearing mounted on a cover that is integrally fixed to the hub on an upper side of the shaft to rotate in a body with the hub when the upper swing structure swivels against the lower driving structure and to be in frictional contact with an upper surface of the shaft to rotatably support the shaft in the axis direction.

1 . A swivel joint for a construction machine that is used to connect hydraulic pipes which supply a flow rate from a hydraulic pump mounted on an upper swing structure that swivels against a lower driving structure to components such as a traveling motor and a steering cylinder mounted on the lower driving structure, the swivel joint comprising:
 a hub mounted on any one of the lower driving structure and the upper swing structure and provided with a hydraulic fluid movement port formed thereon;   a shaft mounted on the other of the lower driving structure and the upper swing structure and rotatably coupled to the hub, the shaft having a hydraulic fluid movement path formed in an axis direction to communicate with the port of the hub; and   a planar thrust bearing mounted on a cover that is integrally fixed to the hub on an upper side of the shaft to rotate in a body with the hub when the upper swing structure swivels against the lower driving structure and to be in frictional contact with an upper surface of the shaft to rotatably support the shaft in the axis direction.   
     
     
         2 . A swivel joint for a construction machine that is used to connect hydraulic pipes which supply a flow rate from a hydraulic pump mounted on an upper swing structure that swivels against a lower driving structure to components such as a traveling motor and a steering cylinder mounted on the lower driving structure, the swivel joint comprising:
 a hub mounted on any one of the lower driving structure and the upper swing structure and provided with a hydraulic fluid movement port formed thereon;   a shaft mounted on the other of the lower driving structure and the upper swing structure and rotatably coupled to the hub, the shaft having a hydraulic fluid movement path formed in an axis direction to communicate with the port of the hub; and   a planar thrust bearing mounted on the hub so as to be in frictional contact with a plate that is integrally fixed to a lower side of the shaft and to rotatably support the hub in the axis direction when the upper swing structure swivels against the lower driving structure.   
     
     
         3 . The swivel joint according to  claim 1 , wherein the planar thrust bearing is formed of an oil-impregnated sintered metal material. 
     
     
         4 . The swivel joint according to  claim 1 , wherein the planar thrust bearing is formed of an oil-impregnated plastic material. 
     
     
         5 . The swivel joint according to  claim 1 , wherein the planar thrust bearing is formed of a bronze metal material. 
     
     
         6 . The swivel joint according to  claim 1 , wherein the planar thrust bearing is formed of a combination of a bronze metal material and a graphite material. 
     
     
         7 . The swivel joint according to  claim 2 , wherein the planar thrust bearing is formed of an oil-impregnated sintered metal material. 
     
     
         8 . The swivel joint according to  claim 2 , wherein the planar thrust bearing is formed of an oil-impregnated plastic material. 
     
     
         9 . The swivel joint according to  claim 2 , wherein the planar thrust bearing is formed of a bronze metal material. 
     
     
         10 . The swivel joint according to  claim 2 , wherein the planar thrust bearing is formed of a combination of a bronze metal material and a graphite material.